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R -8580
TEST PROCEDURES (CONT’D)
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PROCEDURE
LETTER
COMPONENT TEST
CONVECTION HEATER TEST
Make sure the convection heater is fully cooled and test as follows;
a. Disconnect wire leads and measure the resistance with an ohmmeter. On the R x 1 scale, the
resistance between the convection heater terminals should be approximately 38 ohms.
b. Disconnect wire leads and measure the insulation resistance with 500V - IOOM R insulation
resistance meter.
The insulation resistance between convection heater terminal and cavity should be more than
0.5M R.
K
THERMISTOR TEST
Disconnect connector-E from the control unit. Measure the resistance of the thermistor with an
ohmmeter. Connect the ohmmeter leads to Pin No’s E-3 and E-4.
Room Temp. Resistance
20 “C - 30 “C Approx. 350 n - 155 S2
If the meter does not indicate above resistance, replace the thermistor.
L
DAMPER MOTOR TEST
When the power cord is plugged into the wall receptacle, and 240 volts A.C. is supplied to the
damper motor the motor operates until the damper is opened and the damper switch closes. Then
the damper motor stops operation.
If the damper motor does not operate, check for input voltage by A.C. volt-meter at the motor.
1. Disconnect the power cord from the wall receptacle.
2. Disconnect the wire leads of motor and connect the meter leads to the wire leads of main wire
harness.
3. Reconnect the power cord into the wall receptacle.
If 240 volts A.C. is indicated at the wire leads, replace the motor.
Not indicated, check the wire harness and the relay unit.
(RD82EOl U)
M
DAMPER SWITCH TEST
Disconnect the wire leads from the switch terminals and connect ohmmeter leads to the common
(COM) and normally open (NO) terminals of the switch.
1.
When switch actuator is pushed by the damper motor cam, the meter should indicate a closed
circuit.
2. When the power cord is plugged into the wall receptacle, the damper motor operates and
damper cam starts to rotate.
The switch actuator is released the meter should indicate an open circuit.
If improper operation is indicated, replace the damper switch.
(RD82702U)
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